What are the specific trade offs, the ones that come directly to mind now are:
1 - Then moon is only 3 days away and can be reached at any time
while Mars is at best 6 months away and this is only once every 2 years.
2 - Mars has water
while so far water on the Moon looks unlikely
3 - Mars has a day / night cycle close to Earth's
while the Moon's cycle is 28 time longer.
4 - Mars has a slight atmosphere
while the Moon is hard vacuum (however, you would still need the same level
of protection so from a livability perspective this may be a moot point
etc... (please feel free to expand this list)